Add `view references` to the sidebar

When displaying event details, a button next to event parameter values allows the user to list other events that contain the same value either by reference or value.

To the right of a value, a new button exists:

Clicking this icon will update the sidebar to a new view, Find references:

For each list item, badges indicate how the value was matched:

A match by Value indicates the value searched is contained in another event by substring match.
A match by Reference indicates the value searched has been found in another event via the object_id property.

Start at the event-details view and its sidebar, then trace how parameter values are rendered and how event searches use the object_id property. Add the reference action, the Find references sidebar view, and Value/Reference match badges; done means matching events are listed according to the behavior shown in the issue screenshots.